Nothing leaves the tab
No uploads, no accounts, no analytics on what you paste. The tool runs locally, so the data never crosses the network.
Latest version
v2.7.0
230 small tools that run inside your tab.
Format JSON, decode a JWT, make a password, build a cron line, scan a QR code. Each tool has its own page, works as you type, and never sends your data to a server. Install once with one command.
npm install -g mevebu
Needs Node.js 18 or newer. Start it with mevebu after install.
230
browser tools
20
categories
0
runs in your tab
What mevebu is
A private toolbox for the small jobs that do not deserve a whole app.
Some tasks are too small for an app and too sensitive for a random website. Pasting a token into a stranger's page, uploading a CSV to a converter you do not know, signing up to measure a word count. mevebu is built for exactly those: one page per job, plain HTML and JavaScript, and your input stays on your device.
Fast because it is small
Plain HTML and vanilla JavaScript. No framework, no loading spinner, and most tools update as you type.
Works on your machine
The package ships the whole app. Once installed, it runs from your computer with no server behind it.
What is inside
230 tools across 20 categories.
You get one clean page per tool, each with its own address so you can bookmark the one you use every day. Here is a sample of what is shipped.
Developer
JSON formatter and validator, JavaScript minifier, YAML to JSON, JSON to TypeScript, regex tester, cron builder, and JSON diff.
Passwords and keys
Password generator, JWT decoder and generator, hash generator, UUID, bcrypt, HMAC, and TOTP. All computed on your device.
Math
Percentage calculator, percentage change, discount, profit and margin, standard deviation, and a scientific calculator.
Convert
Base64, URL encoder, case converter, number base, image converter, favicon converter, and PDF tools.
Web and SEO
Meta tags, Open Graph tags, robots.txt, sitemap XML, canonical tag, and a live search preview.
Design
Color picker, color palette, gradient generator, contrast checker, box shadow, and CSS clamp.
Open the full list on GitHub
Press Ctrl+K inside the app to search every tool by name or by what it does.
How it works
One install. Then every tool is a local page.
mevebu is an npm package that serves a folder of static pages from a small local server. There is nothing to configure and no account to create.
-
Install the package
One global install puts the
mevebucommand on your machine, along with every tool.npm install -g mevebu -
Start it
Run
mevebu. It starts a small server and opens your browser on the home page.Ctrl+Cstops it. -
Use a tool, close it, forget it
Tools are plain pages. They keep working between restarts, and the port stays stable so your bookmarks keep working too.
Command options
Everything else has a sensible default. These flags are there when you need them.
| Flag | What it does |
|---|---|
-p, --port | Try this port first. Falls back to 5678, then 5432, then any free port. |
-d, --dir | Serve a different folder. Defaults to the bundled tools. |
--no-open | Do not open the browser. |
-v, --version | Print the version and exit. |
-h, --help | Print the help and exit. |
Privacy
Your input never leaves your browser tab.
This is not a policy promise that depends on our servers behaving. There is no server in the loop for the tools themselves. The page you open is the program, and it runs in your browser.
- You run it. The software runs on your machine. Nothing about your session is reported back.
- No account. There is no sign up, no login, and nothing to remember.
- MIT licensed. The source is open. You can read it, fork it, and check the claims against the code.
terminal
# read it yourself: the whole app is served from this folder
npm root -g
ls "$(npm root -g)/mevebu/mevebu"
# and check the tools for outbound calls
grep -rn "fetch(\|XMLHttpRequest" "$(npm root -g)/mevebu/mevebu/libs/js/tools"
# the only hit is inside a string the API builder prints,
# not a request the tool makesFAQ
Questions people actually ask.
Is mevebu really free?
Yes. It is MIT licensed, with no paid tier, no account, and no usage limit.
Does it upload or store what I paste?
No. Your input is processed in your browser tab and is never sent to a server. There is no backend for the tools.
Do I need Node.js?
Yes, version 18 or newer, because mevebu is installed and started through npm. You only need it to install and run mevebu itself.
Which port does it use?
It tries 5555 first, then 5678, then 5432, then any free port. The first three stay stable between restarts, so your bookmarks keep working. You can pick one with -p.
Can I add my own tool?
Yes. Create one file in the tools folder, export a mount function, and add one entry to the registry. The catalog, search, and category pages pick it up automatically. Point --dir at your folder to serve it.
Which languages does the interface support?
English, Indonesian, Bahasa Melayu, Spanish, and Simplified Chinese, in both the shell and the tools.
Install it once. Then it is yours.
One command, no account, and every tool on your own machine.
npm install -g mevebu
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